The present invention relates in general to a motor-vehicle dual-clutch transmission with six or seven forward gears and reverse gear, and more specifically to a servo-assisted gearshift control device for a transmission of this type.
A gearshift control device for a robotized gearbox, in particular for a gearbox with six forward gears, is known from European Patent EP-B-1 216 371 and comprises four shift forks, each of which is slidably mounted along a respective stationary rod fixed to the gear case so as be alternatively movable to first and second engagement positions, each corresponding to the engagement of a respective gear, eight single-acting hydraulic actuators associated in pairs to each fork to control the movement thereof to the first or second engagement positions, and a hydraulic control circuit for controlling the eight hydraulic actuators independently of each other. More particularly, the two hydraulic actuators associated to each shift fork are arranged on opposite sides with respect to a nose of the fork which extends perpendicularly to the corresponding rod and act on that nose to move the fork to the first or second engagement positions.
This known gearshift control device has the advantage of allowing to control the hydraulic actuators independently of each other, but it has however the shortcoming of requiring a great number of components, since two hydraulic actuators are provided for each shift fork.